title: Effects of increasing doses of apomorphine during stereotaxic neurosurgery in Parkinson's disease: clinical score and internal globus pallidus activity. Short communication.
abstract: We analysed the firing activity of internal globus pallidus cells in two Parkinson's disease patients undergoing stereotaxic surgery. Both patients showed an advanced rigid-akinetic syndrome with disabling levodopa induced dyskinesias. Apomorphine, intraoperatively administered at doses (1-2 mg) inducing a short but clear clinical improvement without involuntary movements, reduced the pallidal discharge rate by > 50% in both patients. An higher apomorphine dose (2.5 mg), tested in one hemisphere, blocked the firing activity with a time course independent from the occurrence of dyskinesias. These finding suggest that the reduction of internal pallidus excitability is one of the mechanisms underlying the efficacy of dopaminergic therapy, but also that changes in other basal ganglia stations are likely to be involved in dyskinesias.
authors.affiliation: IRCCS Clinica S. Lucia, Università di Tor Vergata, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Stefani
authors.forename: P
authors.initials: P
authors.lastname: Stanzione
authors.forename: A
authors.initials: A
authors.lastname: Bassi
authors.forename: P
authors.initials: P
authors.lastname: Mazzone
authors.forename: T
authors.initials: T
authors.lastname: Vangelista
authors.forename: G
authors.initials: G
authors.lastname: Bernardi
mesh_terms: D000978:Antiparkinson Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001058:Apomorphine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D018491:Dopamine Agonists / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004409:Dyskinesia, Drug-Induced / Q000150:complications / Q000503:physiopathology; D004594:Electrophysiology; D005917:Globus Pallidus / Q000187:drug effects* / Q000503:physiopathology; D006801:Humans; D007432:Intraoperative Period; D007980:Levodopa / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology / Q000601:surgery; D013238:Stereotaxic Techniques
chemical_list: D000978:Antiparkinson Agents; D018491:Dopamine Agonists; D007980:Levodopa; D001058:Apomorphine